Heretofore, various types of packing assemblies have been provided in wellheads between an inner tubing hanger and an outer supporting tubing head or bowl on which the tubing hanger is seated or supported. For example, U.S. Pat. No. 3,976,130 dated Aug. 24, 1976 shows a packing for a wellhead assembly which is secured to an inner pipe or casing and is movable with the casing upon expansion thereof resulting from high temperatures. U.S. Pat. No. 3,457,992 dated July 29, 1969, for example, shows a packing compressed between a casing hanger and a tubing head with the compressed packing positioned between a lower supporting ring and an upper shoulder on the casing hanger. However, none of the prior art shows a packing assembly between an inner tubing hanger and an outer supporting head or bowl which includes an upper piston like metal ring which is urged downwardly against packing rings by a suitable lubricant or the like after the inner tubing hanger is fully seated on the supporting head or bowl.